The Poorly Targeted Gene

Stephen L. Talbott

From In Context #18 (Fall, 2007)

As we were preparing to write an introduction to our “nontarget effects of genetic engineering” project, two articles came to our attention. One, appearing in the New York Review of Books (July 19, 2007) and written by the prominent physicist, Freeman Dyson, predicts a future of "user-friendly" genetic engineering kits. The first step, he says, has already occurred: genetically modified tropical fish with new and brilliant colors have appeared in pet stores. Still to come are do-it-yourself kits for gardeners to “breed” new roses and orchids, for animal lovers to create previously unknown varieties of pigeons, parrots, lizards, and snakes, not to mention dogs and cats. “Designing genomes,” claims Dyson, “will be a personal thing, a new art form as creative as painting or sculpture." Then the final step in the "domestication of biotechnology” will be biotech games designed like computer games for children down to kindergarten age but played with real eggs and seeds rather than with images on a screen. Playing such games, kids will acquire an intimate feeling for the organisms that they are growing. The winner could be the kid with the prickliest cactus, or the kid whose egg hatches the cutest dinosaur.

Freeman acknowledges that these games “will be messy and possibly dangerous,” but he seems to have little doubt about the scientific precision of the underlying procedures. “Guided by a precise understanding of genes and genomes instead of by trial and error, we can within a few years modify plants so as to give them improved yield, improved nutritive value, and improved resistance to pests and diseases.”

The second article, from the New York Times (July 1, 2007), pointed to the vanishing hope for genes with clearly defined and well understood functions. The expectation for the “industrial gene” had been that, whatever organism it came from, it would “fit neatly and predictably into a larger design — one that products and companies could be built around, and that could be protected by intellectual-property laws.” According to Jack Heinemann, a professor of molecular biology in the School of Biological Sciences at the University of Canterbury in New Zealand, the industrial gene was supposed to be one that can be “defined, owned, tracked, proven acceptably safe, proven to have uniform effect, sold and recalled.”

But that gene, it is now clear, doesn't exist. As the Times article summarizes it:

Evidence of a networked genome shatters the scientific basis for virtually every official risk assessment of today's commercial biotech products, from genetically engineered crops to pharmaceuticals.

Actually, that the industrial gene doesn't exist has been known for a long time, at least by those who cared to look. The strange thing is the disconnect between this knowledge and the widely circulated utopian expectations of the sort we heard from Freeman Dyson. And that brings us to The Nature Institute's “nontarget effects of genetic engineering” project. We believe that public knowledge of the imprecise, often unpredictable nature of genetic manipulation needs to become widespread, and based on this knowledge the public will be much less likely to be swayed by wild claims about the results of biotechnology.

As an example of our project, you will find accompanying this article, below, the subject-lines from some of the entries in our 2008 online public catalog. The catalog provides convenient access to information that is otherwise buried in the technical literature.

 

Some unexpected effects of genetic manipulation

  • Dandelions manipulated to have compound leaves show irregular leaf form and do not flower.

  • Apple trees over-expressing a fruit-ripening enzyme lacked flowers and had malformed stomata and altered composition of cell walls.

  • Plants [Arabidopsis] producing a biodegradable polyester were smaller, never produced seeds, and showed severe changes in metabolism.

  • Barley expressing a heat-stable enzyme showed highly variable expression of the enzyme, an anomalous distribution of expression in the grain, and dramatically reduced weight of individual grains.

  • Root nodule bacteria with Bt transgene tended to displace non-manipulated bacteria in legume root nodules.

  • Canola plants over-expressing a bacterial phytoene synthase gene also had a reduced level of chlorophyll, changed structure of plastids, changed composition of fatty acids, and delayed germination.

  • Bt maize has higher lignin content.

  • Pineapple plants with transgenes for fungus and herbicide resistance had altered biochemical make-up.

  • Potatoes with altered sugar metabolism have changed levels of many metabolites thought to be independent of sugar breakdown, including amino acids, which showed "massive elevation."

  • Herbicide-resistant soybean plants were shorter, with less chlorophyll, lower weight, and increased susceptibility to stem-splitting at high temperatures.

  • Sugarcane plants with lectin transgene for stemborer resistance showed altered growth.

  • Flavonol-enriched tomatoes had altered levels of at least 15 other substances.

  • Wheat with scab-resistance transgene was not scab resistant and showed localized death of leaf tissue.

  • Wheat expressing transgenic glutenin showed reduction in yield, varying production of glutenin, and altered morphology.